Definitions
To help the viewer, all photographic terms used on this site are explained in this section.
A
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Aperture
Aperture priority
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This refers to the size of the opening in the lens through which light can pass. It is denoted as f/xx, where xx is a number that typically ranges between 1.8 and 64, although numbers beyond this range are possible in some lenses.
A smaller number represents a larger opening, while a larger number represents a smaller opening. Aperture is measured as the focal length of the lens divided by the physical size of the opening. Aperture priority is a camera setting, typically denoted as A or Av, that allows the user to select a specific aperture in the lens, while allowing the camera to select the shutter speed required to achieve the correct exposure.
The main purpose of using aperture priority mode is to control the depth of field. Large apertures produce shallow depth of fields. Shallow depth of fields are useful to reduce distractions in the background of an image. Small apertures produce large depth of field, which is useful in landscape photography, where objects in the foreground, middle, and background need to be in focus. Aperture priority is one of 4 main exposure modes typically found in cameras. Other modes are shutter priority (user selects shutter speed and the camera selects aperture to achieve correct exposure), manual (user selects both aperture and shutter speed) and program or auto (camera selects both aperture and shutter speed. |
B
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Bokeh
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This term refers to the aesthetic quality of the blur in out-of-focus areas of an image. It is related to how a lens renders out-of-focus points of light.
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C
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Composition
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D
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E
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Exposure
Exposure compensation
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F
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Focal distance
Focal length
Focal plane
Focus
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H
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Highlights
Histogram
Hot shoe
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I
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ISO
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M
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Macro lens
Matrix metering
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P
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Polarizer filter
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S
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Shutter
Shutter Priority
Shutter speed
Spot metering
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A shutter is a component of a camera that allows light to pass from the lens to film or sensor for a specific duration of time, in order to record an image on the film or sensor. While the camera is not in operation, the shutter remains closed, preventing any light from passing onto the film or sensor. At the point a picture is taken, the shutter opens up, allows light to pass through for a specific period of time, and then closes again, sealing off any light. The duration of time that the shutter remains open is called shutter speed.
Shutter priority is a camera setting, typically denoted as S, T or Tv, that allows the user to select a specific shutter speed, while allowing the camera to select the aperture required to achieve the correct exposure.
The main purpose of using shutter priority is to control how motion is recorded in the image. Slow shutter speeds allow moving subjects to become blurred, adding a sense of motion. Fast shutter speeds can freeze motion, recording details in the subject sharply. Shutter priority is one of 4 main exposure modes typically found in cameras. Other modes are aperture priority (user selects aperture and the camera selects shutter speed to achieve correct exposure), manual (user selects both aperture and shutter speed) and program or auto (camera selects both aperture and shutter speed. Shutter speed is a measure of the duration of time that the shutter remains open, allowing light to pass from the lens onto the photographic film or electronic sensor, to record an image. Shutter speed is measured in seconds. "Fast" shutter speeds are typically in the range of 1/250 second to 1/1000 second. These shutter speeds are useful for freezing, or stopping, motion within the image. "Slow" shutter speeds are typically 1//125 second or slower. These shutter speeds are useful for blurring motion within the image.
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T
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Tone
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